Superheater



J. E. BELL.

SUPERHEATER.

APPUCAHDN HLED 0m11.191s.

Patented Mar. 14, 1922Y A fidi' J. E. BELL. SUPERHEATEH.

APPLICATION FILED DEC. III ISH).

Patented Mar. 14, 1922.

s smears-SHEET 2 UNITED STATES ,MrEr/iirY OFFICE.

JOHN E. BELL, 0F BROOKLYN. NEW YORK. ASSIGNOR TO POWER SPECIALTY COMPANY,

OFNEW YORK. N. Y.. A CORPORATION 0F NEW YORK.

SUPERHEATER.

Specification of Letters Patent. i Patented )hu- 14 1922 Application tiled December 11, 1.919. Serial No. 344.114.

To al] zr/iofn if muy com-ern.'

Be it known that l. .lons l. BELL. a citizen ot' the lnited I*tutes ot' .\merica. residing at Brooklyn. in the county of Kiligs and State ot' New Yorlnhave invented certain new and useful Improvements in Superheaters. of which the following is a full, clear.. and exact description.

In the case of any of' the usual types of steam boilers. which are exemplified. for in@ staure. in liabcock Wilcox. Heine or Stirling boilers. the problem ot superheatin;l the steam. particularly undeil the prei'ailing demand Vfor high pressure servire and high degrees of lsuperheat. is one which has called upon ste-.im engineers to expend much effort to comply with the connnercial requirements. lrimarilv. of course. practical conditions necessitate the use ot relatively small heating surface. but this. when high temperatures or superheat are demanded. involves their protection l'roni the hot gases to prevent their being burned ont. and for this purpose the gases must he caused to sweep more or less of the boiler heating surfaces before they are permitted to impinge upon the superheater. 'l'his provision is met in prartically all forms of boiler and arrangenients of' superheaters now iny use. but the difliculty in practice is that too much of' the boiler heating surt'aee must generally be passed by the hot gases before they reach the superheater, or else the latter must be plared in a'n iin-onrenient iosition, such as where their support wouh he dit'- ficult or the radiation losses would be nnneeessurily large. or extra space outside of the boiler setting would be required. Other and man)v disadvantages result when prius tical designs are attempted.

Recognizing the fact that the tempering ot the turn-.ice gases before they reach the snperheater is a irai-tical necessitiv and, at the same tinnsee ing to obtain a high degree of superheat with a relativel)v small heatingr surface I have devised a novel arrangement for superheaters which is applicable to many t'orms of boiler and-more particularly to the standard types above mentioned. l accordingly place the super i heater in the position where eeonomieal conbetween it and the lire so that the said boiler heatingsurf'ace serres as a protective shield which tempers the gases before they reaeh the superheater tubes.

This ma)F he done in a variety of ways, but preferabtr by placing the superheater hack otl the bridge, wall beneath the boiler. and protecting it h v altering the direction of the first row of boiler heating tubes and causing them to pass through horizontal manifolds so disposed as to provide a set ol' horizontal parallel tubes immediately above the superheating surface.

"t The superheating surface I arrange in horizbntal rows of tubes connected to manifolds in any proper manner. and to better meet the demands of'practical use I divide the superlieater tubes into two groups separated b'va diridingor partition wall which constitutes a forni of' batiie. This wall is an important feature since it affords a ready means of' adjusting or regulatirngr the amount ol' superlieat by its control of the volume of' gases which are caused to pass.the snperheater. In other words. it' more superheat is required this wall is built higher so that a greater amount ot' hot gases will be forced over the superheater. Un the other hand if less superheat is needed the wall is built loweraml the volume of' defieeted gases correspondingly diminished.

This invention requires certain specific details ot' construction and ydesign Vt'or the accomplishment of the best results. but these will-be hereinafter described in the following description in ii'hieh reference is made to thil accompanying drawings. i

Fig. l. is u vertieal sectional view of a boiler of the Stirling type to which my in1 provenient is a )plied Figs. 2 ant 3 are sectional'- details ot'V modified arrangements of the superheater tubes. and t.

Fig. l is a vertical sectional view of' another type of' boiler, that known as a Babcoek & Wilcox. with the improvement applied Lhereto. Y

The boilers herein shown, exee't in the particulars noted, are of the usua form ot construction known in the art, and are selec-ted merely for showing the wide diversity of types to which the invention is applicable. In Figs. 1, 2 and 3 are the eonventional upright banks of tubes connecting the lower drum 4,v with the three upper drains 5.

nace over the tubes The ordina-ry construction is, however, departed from by bending out the outside or front. row of tubes (i, and connecting them to horizontal manifolds 7, which enter the lower drum and which form a horizontal screen over the superheater S, mounted in a recess behind the bridge wall Sl.

'Back of the upright row of tubes 6 is a batllc 10, which extendsl partly up from the level of the bridge wall, and from the front upper drum 5 down to near the lower drum 4 is an extended battle 11 between the second and the third row of upright tubes ot' the first bank.

liv this means the hot gases. as indicated by the arrows, pass upward from the furt3. then downward between thc battles 1l) and 1l sweeping the second row of tubes of the first bank and then upward, followingl the usual course in boilers of thistype.v

Associated with thc superheater 8, whose tubes anl luirizontally disposed, is a battle' l which may be supported and constructed in any suitable manner. but which projects up into the path of the gases and diverts a certain proportion of them down over one part ot' the superheater tubes and up over the other. ln .this way any proportionate vamount of the total volume of gases may be caused to sweep the superheater after they have swept the lirst row of boiler tubes (i and passed through the horizontal manifolds 7. These gases may be still further tempered, it' need be, by placing the bathe 1l back of the third or outer row of upright tubes of the tirst bank.

Referring to Fig. 4 as illustrative of a radicall different type of boiler: Back of the brit ge wall a suitable recess or chamber is provided for the. superheater and over the latter arc the horizontal manifolds 7 connected to the lowermost row ot boiler pipes (i at one end and to the rear boiler header 13 at they other. 'lhe tube-s 6 are properl f bent down for lthis purpose and above tliciu or preferably above the second row of tubes a ballile 1l is placed that imiarts to the How ol hot gases the directions indicated by the arrows.

' In this figure the superheater tubes are shown as divided into' two distinct groups 14 and 15 and thc dividing partition or bafiie l2 is carried up between the two groups. bciu; r cut away beneath them to afford a free passage for the gases.

()ne of the subordinate features of this invention which contribute to its success is well illustrated in this figure in connection with Figs. 2 and 3. The inlet ypipe lti trom the boiler is connected to the middle of the superheater header l?, while the opening 18 from the outlet header 19 instead of being at the middle is at the end of said header.

The position of these openings is worked ont so as' to produce compactness of design. It moreover insures an ideal distribution of steam throughout the superheater tubes and in a general direction counter to that of the heating gases. Without increasing the length of the headers, it permits a staggered disposition of the superheater elements by which those in the upper row are placed directly above the spaces in the lower row, and furthermore in such an arrangement as shown in Fig. 4, this staggering is oppo- 'sitely arranged on.the two sides of the baie wall'which tends to a better contact of the surface with the heating gases which pass below the wall.

Another important feature of the improve ment isdue to the relatively small proportion of the high temperature gases which sweep the superheater tubes. This is an ele- 85 ment Vof safetywhen firing up the boiler and before steam begins to flow through the superheater. The lmited amount of heat to which lthe superheater surface is exposed is not sufficient, under these conditions, to burn out the superheater as might be the `case were all the gases from the fire caused to )ass over it.

iiferent arrangements of superheater tubes are possible and practicable. ln Fig. 2 the two rows are connected in multiple to the headers, while in Fig. 3 they are in series. In either case the supports are all independent of the boiler and may be simply and economically designed.

The construction shown and described may be widely modified. as will nowr be evident, without departure from the invention.

lhat I claim is:

l. The combination' with a water tube boiler ot a superheater placed below but in proximity to the tubes of such boiler, and battling which causes the hot gases to sweep the boiler tubes and diverts a portion of such gases from their normal path over the superheater tubes. a portion of the boiler tubes being bent from their norm-.1l position to form a protective shield over which the said diverted gases pass before they reachth'e superheater tubes. 115

2. The combination with a water tube boiler of a superheater placed below but in proximity to the boiler tubes, and bathing causing the hot gases to sweep the boiler' tubes and divertingr a portion of such gases from` theirinormal path causing the gases to swee the superheater tubes, a portion of the boi ei tubes being bent from their nor? mal position and carried in a horizontal row over the superheater 'so that the said drerted gases must sweep such horizontal water tubes before reaching those of the superheater.

3. The combination in a. water tube boiler of a superheater placed below but in prox- 130 Y gases and causing the same a imity to the water tubes, bafllin causing the hot gases to sweep over the oiler tubes, and diverting a portion of said gases from their normal path over the boiler tubes and causing the same to sweep over the superheater tubes, a ortion of the boiler tubes from one end o the boiler being carried in a horizontal row over the superheater and manifolds to which said tubes and those leading to the other end of the boiler are connected, said horizontal tubes forming a protective shield over which the said diverted gases pass before reaching the superheater.

4. The combination in a water tube boiler of a superheater placed below but in proximity to the water tubes, the outer row of boiler tubes or those nearest the tire bei bent from their normal position and carrie over the superheater, a baile 'for causing the gases to sweep over the said bent tubes, and a baie between the boiler and vthe superheater for detlecting afpprtion of the r passing the water tubes over the superheater to sweep the tubes of the latter.

5. The combination with a water tube boiler of a superheater with horizontal tubes laced beneath the same, the outer row of boi er tubes or those nearest the fire being bent from their normal position and carried over the superheater, of baffles for deflecting the gases from the boiler tubes and causin a portion of the same to im in upon t e superheater, and a vertical a e at the middle oint of the superheater.

6. The com ination with a water tube boiler, of a superheater with horizontal tubes laced beneath the same, the outer row of boi er tubes, or those nearest the fire being bent from their normal position and carried over the superheater, of'baliles for defiecting the gases from the boiler tubes and causlng a portion of the same to impin e upon the superheater and a vertical ba e passing through the center of the superheater and dividing its tubes into two grou s through which a proportion of gas ctermined by the height of said bafiie passes in op osite directions.

7. `he combination with a water tube boiler of a superheater with horizontal tubes placed beneath the same and headers therefor, the outer row of boiler tubes or those nearest the fire being bent from their normal position and carried over the superheater, bafiling for directing the flow of gases over such bent tubes and to the superheater, a vertical baiiie between the superheater tubes dividing them into two groups, a steam pipe from the boiler connected to the middle of the superheater inlet header, and a steam pipe connected to the end of the snperheater outlet header.

8. The combination with a water tube boiler, of a superheater having horizontal tubes placed beneath the tubes of the boiler,

a horizontal row of tubes connected in series with `the outer row of said boiler tubes or those nearest the fire and placed immediatel over.- sa'id superheater, bales for causi g the hot ases to pass over said outer row of boiler tu s, and over the horizontal tubes connected therewith, and a vertical balle for deecting a proportion of the vgases downward and upward over the supereater tubes which is determined by the height of said baille.

In testimony whereof I hereunto affix my signature.

JOHN E. BELL. 

